code: def cleanup_backend():
      if NervanaObject.be is None:
          return
      NervanaObject.be.cleanup_backend()
      NervanaObject.be = None
  
file_path: neon/neon/backends/__init__.py
imports: import atexit
  import logging
  import numpy
  from neon import NervanaObject
  from neon.backends.autodiff import Autodiff
  from neon.backends.util.check_gpu import get_device_count
  from neon.backends.util.check_mkl import get_mkl_lib
  from neon.backends import nervanacpu
label_desc: Use image node_id 2 for calling a global function with example usage: cleanup_backend() without return types